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The 2 types of prosthetic valves are:
- 1. Mechanical
- 2. Bioprosthetic
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Why do patients have prosthetic valves?
- 1. When medication isn't an option
- 2. Stenosis
- 3. Incompetance
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List the 3 main components of mechanical valve with a brief definition
- 1. Occluder - moving component (ball) - comparable to leaflets
- 2. Restraining System - restricts motion of occluder (cage) - comparable to chordae tendinae
- 3. Sewing Ring - attaches prosthesis to vessel - comparable to pap muscles
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List the 3 main mechanical valves
- 1. Ball & Cage
- 2. Tilting Disc
- 3. Bi-Leaflet
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The most commonly used mechanical valve is __________________ because it _______________ _________________ similar to native valve.
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What profile is a bileaflet mechanical valve?
Low profile (not as much movement)
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List 2 disadcvantages for the mechanical prosthetic valves:
- 1. Lifetime anticoagulation drugs
- 2. Increased thromboembolic events
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2 types of bioprosthetic valves are:
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The main disadvantage of bioprosthetic valve is ___________________________________.
Doesn't last as long as a mechanical valve
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Other prosthetic devices are: (2)
- 1. Valved Conduits
- 2. Carpentier Ring
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What's a valved conduit used to repair? What material may it be? (2)
- Some types of congenital heart disease
- Homograft or artificial such as Gore-Tex or Dacron
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Carpentier Ring is used to repair_______________________. (Durand)
What is a carpentier ring and how is it used?
What does it resemble?
AV valves
Flexible ring that's sewn into annulus to help support the native ring.
Resembles MAC
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Define: Pannus Formation
Fibrous ingrowth of tissue
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Define Dehiscence
Sutures of sewing ring loosen
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List complications of a mechanical & bioprosthetic valves seen on an echocardiogram: (8) PATTD CH
Which ones are specific to bio vs. mech?
- Thrombus
- Pannus
- Turbulent Flow
- Dehiscence
- Abscess Formation
- Mechanical failure
- Calcification or degeneration of valve (bioprosthetic)
- Hemolysis - RBC damaged as passing through mechanical valve
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Can you tell the difference of Pannus due to endocarditis vs thrombus formation?
No
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All prosthetic valves have higher velocities. Why? T/F
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What does high profile mean? Low profile?
- High = lots of movement Ie: ball & cage
- Low = little motion Ie: bileaflet
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Explain the difference in flow pattern of a prosthetic mitral valve vs a normal MV. Think of the picture you drew.
- Normal flow moves from MV to apex, curves and heads to AO valve.
- Prosthetic is directed toward mid LV anterior wall and then heads out AO valve. Done to avoid thrombus formation
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Doppler of mechanical valves demonstrates valve click. What is valve click, and how can one use this to help with Dx of stenosis?
- Valve click = opening + closing of valve
- Stenosis = higher velocities than expected
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With prosthetic valves the smaller orifice the _________________________ the velocity.
Higher
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What is the MC brand of mechanical valve?
Star Edwards
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What type of low profile mechanical valve is no longer used?
Bjork Shiley
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A problem with mechanical valves is ___________________ PG.
elevated
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MC bileaflet mechanical valve is ________________________.
St. Jude
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What is the MC mechanical valve used?
Bileaflet tilting disc; St. Jude
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Define: Heterograft (Xenograft)
mace from porcine or bovine tissue (animal)
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Define: Homograft
AO valves harvested @ autopsy or dura mater
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Define: Autograft
Patients own tissue (fascia lata, fibrous mmb from thigh muscle)
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What is the name of the procedure when using an autograft?
Ross Procedure
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Name the 3 main components of Bioprosthetic valves:
- 1. Mobile part - constructed of tissue (semilunar valves from pigs, cows or humans)
- 2. Restraining system - stents or struts
- 3. Sewing Ring
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What is a disadvantage of using bioprosthetic valves?
Not as long lasting
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Why would a Dr. choose a mechanical or bioprosthetic valve?
- Mechanical:
- 1. Young
- 2. Renal failure, small valve annulus, high reop risk
- 3. AO root replacement - dissection with severe AI
- Bioprosthetic:
- 1. Elderly
- 2. Chronic anticoag not advised
- 3. High risk of thromboembolism
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All prosthetic valves are inherintly _______________________.
Stenotic
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Larger valve areas have _________________ velocities and PG and _________________ EOA.
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Why when you have a smaller EOA with a higher velocity would the mean PG be lower even though PG is higher?
Less area to trace. Sawtooth shape
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Is prosthetic regurg normal?
Yes
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Name some limitations of prosthetic valves: (4 multi points)
- 1. reverberation, artifact, acoustic shadowing
- 2. Overestimation of transvalvular PG with bileaflet mechanical valves
- 3. Differentiating normal from pathologic prosthetic valve regurgitation
- 4. Detection of valvular vegetations is difficult d/t reverberations
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What always accompanies a vegetation?
Fever
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Whenever you have open heart surgery, expect to see :
paradoxical septal motion
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Why does PISA work well on prosthetic valves?
Because of the forward flow
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What is the MC cardiac trauma?
MVA
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Stented bioprosthetic valves have an appearance similar to ______________________________.
Native AO valve
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Bioprosthetic valve longevity
10yrs
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Why is the apical view not useful when assessing MR or mechanical prosthetic valve?
acoustic shadowing
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